title: Effects of selected metal oxide nanoparticles on multiple biomarkers in Carassius auratus.
abstract: OBJECTIVE
  To study the biological effects of nanoscale copper oxide (nCuO), zinc oxide (nZnO), cerium dioxide (nCeO2) and their mixtures on Carassius auratus.
  
  
  METHODS
  Juvenile fish (Carassius auratus) were exposed to aqueous suspensions of nCuO, nZnO, and nCeO2 (alone and in mixtures) at concentrations of 20, 40, 80, 160, and 320 mg/L. The biomarkers-acetylcholinesterase (AChE) in brain, sodium/potassium-activated ATPase (Na+/K+-ATPase) in gill, and superoxide dismutase (SOD) and catalase (CAT) in liver-were determined after 4 days of exposure. Integrated biomarker response (IBR) was calculated by combining multiple biomarkers into a single value.
  
  
  RESULTS
  AChE and SOD activities were significantly inhibited by all test metal oxide nanoparticles (NPs) at high concentrations (⋝160 mg/L) with the exception of nCeO2. Na+/K+-ATPase induction exhibited bell-shaped concentration-response curves. CAT activity was significantly inhibited at concentrations equal to or higher than 160 mg/L. The order of IBR values was nCeO2 ≈ nZnO/nCeO2 ≈ nCuO/nCeO2 < nCuO/nZnO/nCeO2 < nZnO < nCuO < nCuO/nZnO. The joint effect seemed to be synergistic for nCuO/nZnO mixtures, additive for the ternary mixture and less than additive or antagonistic for the binary mixtures containing nCeO2.
  
  
  CONCLUSIONS
  Concentration-dependent changes of enzymatic activities (AChE, Na+/K+-ATPase, SOD, and CAT) were observed in fish exposed to nanoscale metal oxides. IBR analysis allowed good discrimination between the different exposures and might be a useful tool for the quantification of integrated negative effects induced by NPs toward fish.
authors.affiliation: Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, Jiangsu, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xia
authors.forename: Hai Zhou
authors.initials: HZ
authors.lastname: Zhao
authors.forename: Guang Hua
authors.initials: GH
authors.lastname: Lu
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism*; D001921:Brain / Q000187:drug effects / Q000201:enzymology; D002563:Cerium / Q000633:toxicity*; D003300:Copper / Q000633:toxicity*; D005880:Gills / Q000187:drug effects / Q000201:enzymology; D006054:Goldfish / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D053768:Metal Nanoparticles / Q000633:toxicity*; D011897:Random Allocation; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000633:toxicity; D015034:Zinc Oxide / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D014874:Water Pollutants, Chemical; D002563:Cerium; C030583:ceric oxide; D003300:Copper; D013482:Superoxide Dismutase; D000110:Acetylcholinesterase; D000254:Sodium-Potassium-Exchanging ATPase; D015034:Zinc Oxide; C030973:cupric oxide
keywords: Biomarker; Carassius auratus; Coexposure; Metal oxide NPs